Mercedes-Benz plans to announce Sunday that it has signed French Open champion Li Na to a three-year endorsement contract. The deal is the first major one for the Chinese star since she earlier this month became the first person from her country to win a Grand Slam tournament. The deal is scheduled to be announced at the headquarters of her agent, IMG, in Wimbledon village outside of London. Wimbledon begins next week. For more on this story, read the June 20 issue of SportsBusiness Journal (Daniel Kaplan, SportsBusiness Journal). CNBC's Darren Rovell reports the deal is worth $1.5M annually, though it is "not known how much of that money she will give to the Chinese Tennis Federation." The talks to sign a car deal "were heated thanks to the size of China's population and the growing sales in the country." Li will wear a "patch on [her] right sleeve as part of the deal" (CNBC.com, 6/16).